The frustration felt by both parties is understandable.
Afterall, you did not plan to have any children at this age. Either
decision made, there' may be one seriously upset party.
Apparently, abortion would leave a deep scar on the girl's life and
may also adversely affect her health. If you see her as your future
life partner, would you bear to hurt her health?
On the other hand, forced responsibility may result in an unhappy
family, unless your mindset is changed -- i.e. accept the
responsibility whole-heartedly and work hard to support your
new-found family. If you calm down and decide to take up the
responsibility like a mature man, I'm sure you can look forward to
a blissful life.
Since your parents may not provide you with patient listening ears,
how about going for a counselling session with 1 of the many family
service centres in Singapore? I volunteer with such an
organisation, so am confident that they can provide you with
professional help and link you to people who are experienced in
handling such situations. (Obviously, no one in your family has
faced such an issue before, so an expert in this field could give
you much more reliable advice based on a wide range of
perspectives.) The sessions are either free or very affordable,
depending on your family income.
Your feelings are as important as your girlfriend's, so in order to
ensure that both of you make the right decision and fully
understand the rationale behind the decision, do try out
counselling services. 
